Process for making a fluid-impermeable layer, and an impermeable hose

Abstract

A process for making a fluid-impermeable layer in a hose having one or more resin layers, and / or one or more rubber layers, and / or one or more thermoplastic elastomer layers, in which a metal plating layer as a fluid-impermeable layer is formed by wet plating on at least one of its resin, rubber and thermoplastic elastomer layers. An impermeable hose having a fluid-impermeable layer made by that process. The hose shows a high level of fluid impermeability, and is also excellent in flexibility, since the metal plating layer can be formed with a very small and uniform thickness without having any pinhole.

Description

[0001] 1. Field of the Invention[0002] This invention relates to a process for making a fluid-impermeable layer and to an impermeable hose. More particularly, this invention relates to a process for making a fluid-impermeable layer by wet plating on one or more layers of a hose having one or more resin layers, and / or one or more rubber layers, and / or one or more thermoplastic elastomer layers. This invention also relates to an impermeable hose having a fluid-impermeable layer made by such a process.[0003] In this invention, wet plating means plating for forming a film by dipping in a solution containing a film-forming substance. The mere term "plating" will hereinafter mean wet plating.[0004] 2. Description of the Related Art[0005] A conventional rubber hose used for conveying fuel in a motor vehicle, such as a hose made of NBR-PVC (a blend of acrylonitrile butadiene rubber and polyvinyl chloride), is satisfactory in vibration absorbability and ease of assembly. It cannot, however, ...

AI Technical Summary

Problems solved by technology

It cannot, however, cope satisfactorily with the recent requirements for the high impermeability of a hose, for example, for conveying fuel or a refrigerant in a motor vehicle.

A film formed by metal vapor deposition cannot, however, be said to be very high in fluid impermeability, since it is microscopically a discontinuous film.

As regards a metallic foil, it is not easy to form a foil having a very small and uniform thickness without making any pinhole.

As a result, it is feared that a hose may lack in flexibility.

There is also an economical problem if a hose is made of a metal that is expensive, though it may be excellent in physical properties, such as nickel.

Moreover, in the case of a hose having a bent or corrugated portion, residual stress remaining in a metallic foil as a result of its shaping into such a form is likely to lower the vibration durability of any hose that is liable to frequent deformation due to vibration, like a hose for a motor vehicle.

Therefore, it becomes possible to employ at a relatively low cost any metal, such as nickel, that is excellent in physical properties, but expensive, since the amount in which it is used can be reduced.

It is, however, feared that a metallic foil in a hose having a bent or corrugated portion may have its vibration durability lowered by the residual stress produced during its shaping.

Images